Speaking-telephone



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W. GILLETT. Speaking Telephone. No. 232,705. Patented sept. 2s, 1880..,L

N. PETERSA PHOTO-LITHDGRAPMER. WASHINGTON n C UNI'TED STATES PATENT @Errea HIS RIGHT TO RICHARD SCHERMERHOBN, OF BROOKLYN, N. Y.

SPEAKING-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 232,705, dated September 28, 1880.

Application led December 9, 1879.

To all 'whom t mag/concern Be it known that I, WEBSTER GILLETT, of Ypsilanti, in the county of W'ashtenaw and State of Michigan, have invented certain new and useful Improvements in Speaking-Telephones; and I do hereby declare that the following is a full, clear, and complete description thereof, reference being had to the accompanying drawingswhicl1 are made a part Figure 1 is an elevation; Fig. 2, a plan; Fig. 3, a transverse vertical section through the dotted line a b, Fig. l; and Fig. 4 is a horizontal section through the dotted line a: y,

r 5 v Fig. 1.

My invention consists in an adjustable cylinder containing the lopT conductor, so combined with independent adjusting devices that the point of contact is forced by the acoustic iniuence into the deepest desirable position in the low conductor, whereby is obtained, first, the most perfect conducting medium second, siX deviations of the electric current; and, third, the generation of a current of elec- 2 5 tricity upon the secondary wire of the inductin-coil.

Like letters of reference designate corresponding parts in all of the figures of the drawings.

U and O are metallic rings 5 B, a vibra-tory plate 5 A and A', a frame; S, a mouth-piece;

` E, an opening in the mouth-piece to admit of acoustic action on the vibratory plate, and H an induction-coil. In Figs. 1 and 2, J, K, U, and Y represent the binding-posts. The metallic rings C and C confine between them the vibratory plate B, and are screwed to the frame A and A opposite the mouthpiece opening E. `The anglepiece b is securely fastened to the metallic` the disks P and P between its iiange and the flange of the cylinder F, and thereby holdingA the low conductor N in an oblate form to increase its conductive capacity and to secure results hereinafter specified. O is a metallic bar, which is securely fastcned to the vibratory plate B and abuts against n i. with a shoulder against the pliable elastic disk P'. This compressionscrew R is provided with a milled head, h, and a metallic pin, s, which penetrates the disk P and makes contact with the poor electric conductor N.

D, Figs. 2 and 4, is a metallic post secured 7o to the frame A, and I is a metallic strap connecting the post D with the compression-screw B, which is provided with a jam-nut, d.

By increasing or diminishing the compression upon the poor electric conductor Nits conductive capacity will be increased or diminished. This is accomplished, as shown in Figs. 3 and 4, by means ofthe screw-compres` sion cap G, in combination with the elastic disks l? and P', by the compression-screw R, 8o and by the lateral adjustment of the cylinder F through its arm V in respect to the vibratory plate B and bar O.

Upon connecting the primary wire of the induction-coil H with post D, binding-post Y, 8 5 and the screw M of the metallic ring Gf, and with the binding-post U, as shown iii-Figs. l and 2, the electric influence of the positive pole of a battery, from the binding-post Y, passes through the induction-coil to the post 9o D; thence through the strap I, screw It, pin S, strata N, cylinder F, arm V, angle-piece b, ring C', thence through the wire from the screw M to the binding-post U, making connection with the opposite pole of the battery, and thus forming a circuit through the low electric conductor N. The secondary wire of the induction-coil H is connected with the binding-posts J and K in the usual manner.

An electric circuit having been formed roo through the poor electric conductor N, as specified, it is obvious that any movement or vibration of the vibratory plate B caused by acoustic or other inuences will compress,

through the bar O, the low electric conductorv Aand an increased pressure of the same against the metallic pin S, thus giving six deviations of the electric current. To clearly understand these six deviations of the electric current the following explanation is oered here: The

low conductor being of granulated substance.

conned between the elastic disks, the whole being inclosed in a metal cylinder provided with an inner flange at one end and a screwcap at the other, is so arranged that the low conductor is compressed from without, consequently assuming an oblate form. Every forward stroke of the vibratory plate causes, rst, an increased pressure of the low conductor against the sides of the cylinder; second, an increased pressure against the screw and pin; and, third, an increased surface contact of carbon on the pin, as the elastic disk Pl gives upon the pin for each vibration-that is, lets the pin deeper into the carbon, thus presenting a greater surface-bearing against the low conductor. The deeper the pin can be forced into the low conductor the better will be the conducting medium, the strength of which is proportionate to the deviation of the pressure in the cylinder. By this device an ,increased pressure of the low conductor against the forward and backward strokes are equal it follows that there are altogether six deviations of the electric curren t. A forward stroke of the vibratory plate and bar O, which abuts against the elastic disk P, causes an increased pressure of the low conductor against the pin, and the tendency of the elastic disk P to strip or give upon the pin increases the surface of contact by forcing the pin deeper into the conductor, whereby a current is set up over the secondary wire of the induction-coil. By the back stroke, or return of the vibratory plate to its normal position, currents are produced in the coil of opposite polarity. Therefore, it being understood that any deviation (increased or diminished) of the electric current of the primary wire of an induction-coil will set up and generate a current in the secondary Wire of the coil dependent upon and measured by the deviations of the current in the said primary wire, it must follow that by securing these deviations of the electric current, as before described and speciiied,acoustic iniiuences operating upon the vibratory plate will be transmitted over a wire with great energy, and consequently to long distances and through great resistances.

In my former patent of March 18, 1879, No. 213,283, the point of contact is not adjustable. The necessary adjustment is effected by moving the cylinder containing the low conductor against the point of contact; but in this invention the adjustable cylinder containing the low conductor is held solid after a coarse adjustment has been made, while the refined adjustment is produced by forcing the point of contact deeply into the low conductor.

Having thus described my invention, Iclaim as new and desire to secure by Letters Patent- Y 1. 1n speakin g-telephones, a cylinder for containing the low conductor, combined with separate and independent devices for obtaining a coarse adjustment of the cylinder and a fine adjustment of the contact, substantially as described.

2. The adjustable cylinder F for containing the low conductor N, in combination with the acoustic or vibratory plate B and its arm O and the screw R and its pin S, said arm and pin being arranged opposite to each other and with the lou7 conductor between them, in order to produce a deviation of the electric current, substantially as shown and described.

WEBSTER GILLETT.

Witnesses:

SAMUEL OPPENHEIM, DANIEL G. THOMPSON.

IOO 

